Question: $\left[\begin{array} {ccc} 2& 2& 2& 2& 2\\ 5& 5& 5& 5& 5 \end{array}\right]$ What are the dimensions of the matrix?
The first dimension is the number of rows in the matrix. There are $2$ rows. The second dimension is the number of columns in the matrix. There are $5$ columns. In conclusion, the dimensions of the matrix are $2\times 5$.